Well bit



Feb. 8, 1938. A. c. CATLAND 2,107,626

WELL BIT Filed April 13, 193 6 2 Sheets-Sheet l Feb. 8, 1938. CATLAND2,107,626

WELL BIT Filed April 13, 1936 2 Sheets-Sheet 2 1e .7. c w

Aka/9% Patented Feb. 8, 1938 UNITED STATES PATENT OFFICE WELL BITApplication April 13, 1936, Serial No. 74,164

11 Claims.

This invention relates to a well drilling tool and relates moreparticularly to a roller rock bit.

A general object of this invention is to provide an improved, simplifiedand very efficient roller rock bit.

Another object of this invention is to provide an improved roller bitembodying three circumferentially spaced outer roller cutters operableto cut the well bore to gauge and a pair of inner roller cutters foracting on the inner portion of the well bore, said cutters being relatedto be particularly rapid and eflicient in their drilling action.

Another object of this invention is to provide a roller bit of thecharacter mentioned in which two of the outer roller cutters are mountedor supported entirely independently of the mounting of the innercutters.

Another object of this invention is to provide 39 a well bit of thecharacter mentioned in which two of the three outer cutters aresubstantially longer or thicker than the third outer cutter.

Another object of this invention is to provide a roller bit of thecharacter mentioned in which 7, the cutters are dependably supported forrotation and for easy replacement without the embodiment or inclusion ofa large removable spider or mounting member.

Another object of this invention is to provide a roller bit of thecharacter mentioned in which the inner ends of the cutter carryingbushings or bearings are supported by integral parts of the shank. Wellbits embodying inner and outer roller cutters have usually included acomparatively large removable spider or mounting member for mounting thecutters on the shank and for carrying the inner ends of the cutterbearings or mountings. The improved bit of .the present invention isstronger and more rigid than the typical bits embodying such mountingmembers or spiders, as it embodies parts integral with the shank forsupporting the cutter mountings.

Another object of this invention is to provide a roller bit of thecharacter mentioned in which all the wear receiving parts may be easilyand quickly replaced.

A further object f this invention is to provide a roller bit of thecharacter mentioned embodying novel and particularly effective mountingmeans or supporting means for the cutters.

The various objects and features of my invention will be fullyunderstood from the following detailed description of typical preferredforms and applications of my invention, throughout which descriptionreference is made to the accompanying drawings, in which:

Fig. 1 is a side elevation of the roller bit provided by this invention.Fig. 2 is a bottom elevation view of the bit being a view taken asindicated by line 2-2 on Fig. 1. Fig. 3 is a vertical detailed sectionalview being a view taken substantially as indicated by line 3-3 on Fig.2.

' Fig. 4 is a fragmentary vertical detailed sectional view takensubstantially as indicated by line 4-4 on Fig. 1. Fig. 5 is a viewsimilar to Fig. 4 showing a modified form of cutter mounting means andFig. 6 is a transverse detailed sectional view taken substantially asindicated by line 66 on Fig. 5.

The roller bit of .the present invention illustrated in Figs. 1 to 4,inclusive, of the drawings, includes, generally a shank l0, spaced outercutters A and B rotatably supported on the lower end of the shank l0, anouter cutter C at the lower end of the shank spaced between the cuttersA and B, inner cutters X and Y, and means II for rotatably mounting thecutters C, X and Y on the lower end of the shank ill.

The shank I0 is adapted to be connected with the lower end of a welldrilling string. Suitable means is provided on the upper end of theshank ID for facilitating its connection with the drilling string. Inthe case illustrated in the drawings a screw threaded pin I2 is providedon the upper end of the shank Ill to thread into a socket in the lowerend of a drill collar or connecting member of the drilling string. Asocket or fluid passage l3 enters the shank ill through the upper end ofits pin l2 to communicate with the fluid passage in the drilling string.The lower portion of the shank I0 is formed to receive and carry thecutters A and B and the mounting means ll of the cutters C, X and Y.Three circumferentially spaced legs M, N and 0 project from the lowerend of the shank Ill. The legs M, N and O are substantially equallyspaced and project downwardly and slightly outwardly from the lower endof the shank. The inner sides or surfaces l4, l5 and I6, respectively,of the legs M, N and O, are substantially flat and inclined downwardlyand outwardly relative to the longitudinal axis of the shank. Flatdownwardly and inwardly inclined faces l1, l8 and I9 are provided on thelower ends of the respective legs M, N and O. In accordance with theinvention the legs M, N and O are integral with the shank l0.

The invention provides a leg or projection 20 on the shank l0 projectingdownwardly within the series or spaced legs M, N and 0. The prowhichcarry the cutters A and B.

jection 20 is integral with the shank l0 and is substantially vertical.In the preferred construction the projection 20 is offset from thecentral longitudinal axis of the shank I0 being closer to the legs M andN than to the leg 0. The projection 20 may have a fiat substantiallyvertical inner side and outwardly flared or diverging side surfaces 2|.The side surfaces 2| of the projection 20 oppose the inner surfaces l4and I5 of the legs M and N leaving spaces or pockets A flat bearingsurface 22 is provided on the lower end of the projection 20. Thesurface 22 may be substantially normal to the longitudinal axis of theshank Hi and has a vertical or substantially axial shoulder 23.

The lower end portion of the projection 20 islbifurcated having two armsor branches 24 projecting downwardly and outwardly as well ashorizontally from the projection. The branches 24 have flatsubstantially disc-shaped bearing surfaces 25 spaced from and opposing"the inner surfaces I4 and I5 of the opposing legs M and N. The surfaces25 are substantially parallel with the inner surfaces l4 and I5 of thelegs. Flat walled notches 26 intersect the lower end portions of thesurfaces 25.. It is to be understood that the projectioh 20 and itsbranches 24 are integral parts of the'shank ID.

The outer cutters A and B are in the nature of rotatable roller cuttersfor acting on the peripheral or outer portion of the well Poore to outthe bore to gauge. B are of the same size and arefrusto-conical havingpitched or tapered peripheries. The cutters A and-B have peripheralcutting parts or teeth 21 and 2'! respectively for acting on theformation. In the case illustrated in the drawings the teeth 21 and 21are straight and extend axially of the cutters, it being understood thatthe teeth maybe pitched or spiralled if desired. The outer ends of theteeth 21 and 2'1 are preferably'bevelled off as at 28 and the inner endsof the teeth 21 and 21 may extend or project inwardly from theirrespective cutters A and B. The opposite ends of the cutters A and B maybe fiat and normal as illustrated in Fig. 3 of thedrawings. Acylindrical concentric socket 29 is provided in" the inner end or thecutter A and a similar. socket 29 is provided in the inner end of thecutter B.

The cutters A and Bare supported between the legs M and N and thebranches 24 to rotate about downwardiy and inwardly inclined axes. Themeans for rotatably supporting the outer cutters A and'B comprise ahearing or bushing 30 extending through and rotatably carrying thecutter A and a similar bushing 3|] 2-:- tending through and rotatablycarrying the cutter B. An annular flange 3| is provided on the inner endof the bushing 30 and fits in or cooperates with the socket 29 in thecutter A. An annular flange. 3| is provided on the inner end of thebushing 35" and cooperates with the socket 29 in the cutter B. Theflanges 3| and 3| are adapted to directly "bear on the surfaces 25 ofthe branches 24 and lugs 32 and 32 are provided on the flanges 3| and 3|respectively to cooperate with the notches 26. The cooperation of thelugs 32 and 32 with the notches 26 holds the bushings 30 and 30 againstrotation. A replaceable wear taking washer 33 is provided between theouter end of the bushing 30' and the inner surface ll of the leg M. Thewasher 33 has a shoulder as which cooperates The roller cutters A andwith the face I! to hold the washer against rotation. A replaceable weartaking washer 33 is provided between the,outer end of the bushing 3|]and the inner side |5 of the leg N. The washer 33 has a shoulder 34cooperating with the face l8 whereby it is held against rotation. Asuitable bearing 9| may support the cutter A on the bushing 30 and asimilar bearing 9| may rotatably support the cutter B on the bushing 30.

A pin-or screw 35 is provided to support t-h bushing 30 between the legM and the opposing branch 24. through anopening 36 in the branch 24 toextend through the bushing 30 and its outer end portion is threaded inan opening 31 in the leg M. A screw 35 is passed outwardly through anopening 36 i n the branch 24 opposing the leg N and extends through thebushing 33 to thread into an opening 31 in the leg N. In accordance withthe invention the openings 36 and 31 and the openings 36' and 31" areinclined downwardly and inwardly whereby the cutters A and B arerotatable about downwardly and inwardly inclined axes. mounted as justdescribed project downwardly beyond the lower ends of the legs M and Nand the branches 24 and the cutting edges of their respective teeth 21and 21 are inclined down= wardly and inwardly as they come intoengagement with the earth formation at the bottom of the bore.

.The cutter C is provided to act on the outer portion of the well boreto assist the cutters A and B in cutting the core to gauge and is spacedbetween the cutters A and B to stabilize the bit. The cutter C is in thenature of a roller cutter and in accordance with the invention isconsiderably shorter or of less axial extent than the cutters A and B.The cutter C is provided with spaced peripheral cutting parts 40. Thecutting parts 40 may be straight and axial, as illustrated. A centrallongitudinal opening 4| is provided in the cutter C.

The inner cutters X and Y are provided to act on and cut away theformation at the inner portion of the well bore. The cutters X and Y arefrusto-conical cutters hatdng pitched or inclined peripheries. Thecutter Y is provided with suitable peripheral cutting parts 42 andsuitable teeth or cutting parts 43 are provided on the The screw 35 ispassed outwardly The cutters A and B The means I 'removably supports thecutter C and the cuttersX and Y for rotation about inclined axes betweenthe leg 0 and the projection 20. In the embodiment of the inventionbeing described the means' comprises an integral or one piece bushingmember 44 rotatably carrying the cutters C, X and Y. The member 44 iselongate and is arrangedbetween the inner side of the leg 0 and theprojection 28.

The bushing member 44 is provided with a cylindrical bearing part 45 forrotatably carrying the cutter C and a cylindrical bearing part v45 forrotatably carrying the cutters X and Y. The outer end of the bearingpart 45 is preferably flat and substantially parallel with the innerside |6 of the leg 0. A socket 41 is provided in the outer end of thebearing part 45 and receives a boss 48 on the inner side of the leg 0.An annular shoulder 49 occurs on the member 44 at the inner end of thebearing part 45. The shoulder 49 is flat and normal tothe longitudinalaxis of the bearing part 45.

The bearing part 46 of the member 44 is appreciably longer .than thebearing part 45 and is inclined downwardly and inwardly at a lesserangle than the part 45. An annular thrust shoulder 50 is provided on themember 44 at the outer end of the bearing part 46. The portion of themember 44 occurring between the shoulders 49 and 50 forms a spacerbetween the cuttersC and Y. A socket 5| is provided in the inner end ofthe bearing part 46. A replaceable thrust washer 52 is provided on theboss 48 between the inner surface l6 of the leg 0 and the outer end ofthe bearing part 45. The outer cutter C rotates on the bearing part 45between the shoulder 49 and the washer 52 and the washer receives theend thrusts from the cutter. A leg or shoulder 53 on the washer 52cooperates with the face I9 of the leg 0 to hold the washer againstrotation. A suitable anti-friction bearing 93 may rotatably support thecutter C on the bearing part 45.

The cutter mounting means includes a removable block or cap 54 on thelower end of the shank projection 28. The cap 54 has a flat upper face55 cooperating with the surface 22 of the projection 26 and has ashoulder 56 bearing against the shoulder 23. A flange 51 on the innerside of the cap 54 bears against the inner side of the shank projection28. A cap screw 58 is passed upwardly through an opening in the cap 54and is threaded into an opening 59 in the projection'20 to removablysecure the cap 54 to the projection 20. A'boss 96 on the cap 54cooperates with the socket 5|. A head 58 on the screw 58 is received ina socket or enlargement of the opening in the cap 54. The cuttermounting means I! includes a pin or screw 6| for holding the bushingmember 44 between the leg 0 and the projection 28 and for connecting theleg 0 with the cap 54. A longitudinal opening 62 is provided in thebushing member 44 to receive the screw 6|. The opening 62 is eccentricand inclined with respect to the longitudinal axes of the bearing parts45 and 46. The screw 6| is passed outwardly through an opening 63 in thecap 54 to extend through the opening 62 andits outer portion is threadedinto an opening 64 in the leg 0. The openings 63 and 64 are inclineddownwardly and inwardly with respect to the longitudinal axis of theshank. A head 65 is provided on the screw 6| and is received in a socketor enlargement of the opening 63 in the cap 54.

The cutters X and Y are rotatably carried by the bearing part 46 of themember 44 and suitable roller bearings 66 may be provided to rotatablysupport the cutters on the bearing part 46. In accordance with theinvention the cutter Y surrounds the outer portion of the bearing part46 and its outer end may bear on the shoulder 50. The cutter X isarranged on the inner portion; of the bearing part 46 and its inner endmay bear on the flange 5'! of the block 54. The inclination of thebearing part 46 is such: that the cutting parts 42 and 43 of the cuttersX and Y are substantially horizontal as they come into engagement withthe formation at'the bottom of the well bore. The parts are proportionedand related so that the inner end of the cutter X is adjacent or spaceda slight distance outwardly from the central vertical axis of the shank.

In assembling the cutters C, X and Y on the shank I0 the washer 52 isfirst arranged on the boss 48. The cutters C, X and Y are then as--sembled on the bushing member 44 and the cap 54 is arranged against theinner end of the member 44 so that the socket 5| receives the boss 98.This assembly is then arranged in position so that the boss '48 projectsinto the socket 41 and so that outer end of the member 44 engagesagainst the washer 52. The assembly may be swung on the boss 48 to bringthe cap 54 into proper contact with the projection 28. The screw 6| ispassed outwardly through the openings 63 and 62 and is threaded into theopening 64. The screw. 58 is then threaded into the opening 59 to securethe cap 54 to the projection 28. As illustrated in the drawings the head58 of the screw 58 cooperates with the head 65 of the screw 6| topositively prevent unthreading of the screw 6|.

The invention includes means for flushing the cutters A, B, C, X and Yand for providing a suitable turbulence in the well bore.

the passage i3 and discharges into the space between the leg M and theprojection 20 to effectively flush the cutter A. A similar port 61communicates with the passage I3 and discharges into the space betweenleg N and the projection 26 to flush the cutter B. The shank I0 isprovided with a port 68 which extends downwardly from the passage I3 anddischarges into the pocket or space between the leg 0 and projection 28.

means I rotatably supports the cutters C X H and Y between the body leg0 and the body projection 20. The means comprises a cutter mountingbushing having two sections 10 and 1|. The section 18 carries the cutterC While the bushing section II rotatably carries the cutters X and Y Thebushing section 16 has a downwardly and inwardly inclined cylindricalbearing part 12 rotatably supporting the outer cutter C The outer end ofthe bearing part 12 is flat and adapted to bear outwardly against theboss 48 on the inner side of the leg 0. A replaceable thrust washer 52is arranged on the boss 48 and is held between the inner side of the leg0 and the outer end of the bearing part 12. The washer 52 has a surface53 -cooperating with a lower face |9 of the leg 0 to hold the washeragainst turning. An annular thrust shoulder 49 is provided at the innerend of the bearing part 12. The cutter C rotates on the bearing part 12between the shoulder 49 and the washer 52 The inner section II of themeans M is cylindrical to rotatably carry the two cutters X and Y A lugand groove connection is provided between the sections 18 and H. In thecase illustrated a flat-walled groove 86 is provided in the inner end ofthe section Ill'and a lug 8| on the outer end of the section cooperateswith the groove80. The end of the lug 8| may be rounded to facilitatethe assembling of the sections 10 and "H. The adjacent or opposing endsof the see- A port 69 extends downwardly through the shank ID from Thetious ll! and II may be in direct abutment as illustrated in Fig. 5 Theinner end of the section 1| is flat and normal and bears against theflange 51 of the cap 54. The cutters X and Y are arranged in end to endrelation on the section H between the end of the section and the flange51 Suitable bearings 66 may rotatably support the cutters -X and Y onthe bushing section TI. The block or cap 54 is removably 10 secured tothe shank projection 20 by a screw through the openings 62' and 62* tothread into an inclined opening 64 in the leg 0. The head of the screw58 cooperates with the head of the.

screw 6| to prevent unthreading of the screw 6|, As the openings 62 and62 are eccentric and inclined with respect to the bearing surfaces ithevsections 10 and H the sections are posian prevented from turning on thescrew 6P.- In operation, the shank I0 is connected with the lower end ofa drilling string which is rotated and fed downwardly in the usualmanner. The cuttersA, B and C project downwardly and outwardly beyondthe .body legs M, N and 0 to cut the well bore to gauge and to form theouter portion of the bore. The inner-cutters X and. Y act to cut awaythe inner portion of the well bore. The cutters A, B, C, X and Y aremounted and related to be particularly rapid and efiicient in theirengagement with the formation. The spacing of the cutters A, B and C issuch that the drill is stabilized or steadied. The screw 35- in addition to retaining the bushing 30 dependably ties the leg M to one of thebranches 24. The screw 35 supports the bushing 30 and securely ties theleg N to the other branch 24. The screw 6| carries the bushing member 44and ties together the leg O'and the shank projection 20. Thus the pinsor screws of the cutter mountings serve to dependably tie together thespaced parts of the integral shank. The cutters are mounted so that theymay be easily and quickly removed for replacement and all the wearingparts of the bit may be easily replaced. The mounting of the severalcutters does not necessitate a large spider or cutter supporting memberand the bit structure is particularly simple and inexpensive.

Having described only typical preferred forms and applications of myinvention, I do, not wish to be limited or restricted to the specificdetails herein set forth, but wish to reserve to myself any variationsor modifications that may appear to those skilled in the art or fallwithin the scope of the following claims.

Having described my invention, I claim:

1. A well bit comprising, a shank, three circumferentially spaced outerroller cutters at the lower end of the shank, two of the outer cuttersbeing of greater axial extent than the third outer cutter, separatemeans supporting said two outer cutters for rotation, an inner rollercutter, and

a single removable member rotatably carrying said third outer cutter andthe inner cutter.

2. A well bit comprising, a shank, three circumferentially spaced outerroller cutters at the lower end of the shank, two of said outer cuttershaving cutting parts of greater length than the cutting parts of thethird outer cutter, removable members removably secured to the shank andend and an integral projection within said series,

each rotatably carrying one of the said two outer cutters, inner rollercutters, and a single removu able member on the shank rotatablysupporting the inner cutters andsaid'third outer cutter for rotationabout inclined axes,

3. A well bit comprising, a shank having a series of circumferentiallyspaced legs on its lower end and an integral projection extendingdownwardly within the series of legs, removable members between the legsand the projections, screws extending through the members and tyingtogether the legs and the projection, and roller cutters rotatablycarried by said members to cut the well bore to gauge, and an innerroller cutter carried by one of said members.

4. A well bit comprising, a. shank having a series of circumferentiallyspaced legs on its lower end and an integral projection extendingdownwardly within the series of legs, inclined bushings arranged betweenthe legs and the projection, connecting members extending through thebushings connecting the legs and the projection and removably supportingthe bushings, and roller cutters rotatable on the bushings.

5. A well bit comprising, a shank having a series of circumferentiallyspaced integral legs on its lower end and an integral projection withinthe series of legs, a block removably secured to the lower end of theprojection, bushings arranged between and supported by two of the legsand the projection, a bushing arranged between and supported by a thirdleg and the block, and roller cutters rotatable on the bushings.

6. A well bit comprising, a shank having a series of circumferentiallyspaced integral legs on its lower end and an integral projection withinthe series of legs, a block removably secured to the lower end of theprojection, bushings arranged between the projection and two of thelegs, connecting. members extending through the bushings and connectingthe legs and the projection, a bushing arranged between a third leg andthe block, a connecting member extending through the said bushing andconnecting the block and said third leg, an outer cutter rotatable" oneach of said bushings, and an inner cutter rotatable on the lastmentioned bushing.

7. A well bit comprising, a shank having a series of threespaced'integral legs on its lower end and an integral projection withinsaid series, integral branches on the projection, removable bushingsarranged between the branches and two of said legs, outer roller cuttersrotatable on the bushings, a block removably secured to the projection,a removable bushing supported between the block and the; third leg, anouter roller cutter rotatable on the last mentioned bushing, and aninner roller cutter rotatable on the said last mentioned bushing. v

8. A well bit comprising, a shank having a series of three spacedintegral legs. on its lower end and an integral projection within saidseries, integral branches on the projection, removable bushings arrangedbetween the branches and two of said legs, outer roller cuttersrotatable on the bushings, a block removably secured to the projection,a removable bushing arranged between the'block and the third leg, aconnecting member extending through-the last mentioned bushing andconnecting the said third leg and the integral branches on theprojection, removable bushings arranged between the branches and two anouter roller cutter on the last mentioned bushof said legs, outer rollercutters rotatable on the bushings, a block removably secured to theprojection, a removable bushing arranged between the block and the thirdleg, a connecting member extending through the last mentioned bushingand connecting the said third leg and the block, an outer roller cutteron the last mentioned bushing, and an inner roller cutter on the lastmentioned bushing, said last mentioned bushing beingsectional-comprising a section carrying the last mentioned outer cutter,and a section carrying the inner cutter. v

10. A well bit comprising, a shank having a series of three spacedintegral legs on its lower end and an integral projection within saidseries, integral branches on the projection, removable bushings-arrangedbetween the branches and two 01' said legs, outer roller cuttersrotatable on the bushings, a block removably secured to the projection,a removable bushing arranged between the block and the third leg, aconnecting member extending through the last mentioned bushing andconnecting the said third leg and the block,

ing, and an inner roller cutter on the last mentioned bushing, said lastmentioned bushing being sectional comprising a section carrying thelast'mentioned outer cutter, and a section carrying the inner cutter,and a lug and groove connection between the said sections.

11. A well bit comprising, a shank having a series of three spacedintegral legs on its lower end and an integral projection within saidseries, integral branches on the projection, removable bushings arrangedbetween the branches and two of said legs, connecting members extendingthrough the bushings to retain the same and connecting said two legswith the branches, outer roller cutters rotatable on the bushings, ablock removably secured to theprojection, a removable bushing arrangedbetween the block and the third leg, a connecting member extendingthrough the last mentioned bushing and con- 1

